Your coccyx, or tailbone, is the lowest portion of your spine. It consists of three to five bones, depending on your personal anatomy, that are fused together. Because it's a hard structure that's not changeable except through surgery or an accident, you can't really exercise to make it stronger or larger.
However, your tailbone is designed to have some slight movement, facilitating a change from a stand to a seated position, for example. If you lose mobility in your tailbone, you feel stiff and potentially experience pain in the very base of your back.
Pilates can help you maintain freedom of movement in the coccyx with specific exercises.
The pelvic tilt is one of the most basic Pilates exercises, but serves as a foundation for your entire practice. It's intrinsic in learning to imprint your spine and engage your core.
How to: Lie on your back with your knees bent, feet planted about hip-width apart. Relax your buttocks but engage your perineum, the muscles around your scrotum or vagina. Inhale and, ever so slightly, tilt your pubic bone up toward the ceiling. Imagine a string pulling the bone up. Simultaneously, press your spine, including your lower spine, into the mat. Hold for 1 to 2 seconds and release. Repeat 5 to 10 times.
You might think of these as reverse rollups. The coccyx curl trains the lift of your tailbone and integrates it with continued movement of the spine.
How to: Engage the pelvic tilt as above. But, instead of releasing back to the mat, keep rolling up from your hips as you inhale. You'll lift your pubic bone, then the lower back, middle back and upper back off the mat into a bridge. Exhale and replace the vertebra slowly back down, starting from the upper back all the way to the back of the pubic bone. Repeat five to 10 times.
Read More: Stretches for a Pain in the Tailbone
Why Some Tailbones Suffer
You may be less concerned with working your tailbone region and more interested in how to relieve discomfort in it. Many Pilates exercises, such as rolling-like-a-ball and roll-ups, tend to irritate it. If you have a sensitive tailbone, it may be extra long or curved in such a way that makes sitting back against it on the floor is uncomfortable. You might want to avoid or modify several Pilates exercises, which can be aggravating.
Ways to alleviate discomfort include using an extra thick mat, doubling up your existing mat or piling two mats together. You may also skip irritating exercises or roll only partially through the range of motion.